Linux Common Commands--su

su 切换用户

Syntax format: su "option" "Username" su [options] [user name]
Attention:

1. There must be at least one space between each element in the SU command and subsequent options and user names
2. If the user name after the command is omitted, the default switch is the root user
3. No password is required when switching from the root user to a normal user, and the root password is required when switching from a normal user to the root user.
   Parameter options:

parameter Options	Explanatory notes
-,-l,--login	Switch user's home directory, System environment and so on again after the switch user class.
-C	Passing a single command to the Shell

Case one:
Switch users


Note: While not adding "-", although the switch to root, but the environment variables are ordinary users, this is the wrong way to switch.
Case TWO:
How can the system automatically start the specified service script with a normal user at every boot?

Simple application of-c instruction

Linux Common Commands--su